No check engine lights and I got 280 miles on the last tank. 4 gallons of E85 is the sweet spot. Car is running great.
gallons of E85: 4.006 @ $1.759/ gallon
gallons of 87 octane: 9.829 @ $2.159/ gallon
ethanol content of tank: 33.10%
octane of tank: 92.27
savings per tank compared to premium @ $2.659/ gallon: $8.52